This invention concerns a process for the facile transfer of alkyl groups between dialkyltrisulfides and alkyl mercaptans. More particularly, it concerns the catalytically induced transfer of one or more tertiary alkyl groups between a di-tertiary alkyl trisulfide and a mercaptan having a higher alkyl group to thereby produce dialkyl trisulfides incorporating transferred alkyl groups and having utility as extreme pressure additives in lubricating compositions.